1. Field of Invention
The invention relates to the technical field of a motor with a rotation detecting device, which is used for electrical equipment mounted on a vehicle or the like.
2. Description of Related Art
Generally, in this type of motor, there is a rotation detecting device which detects the rotational amount of a rotary shaft of the motor for detecting the movement amount or the position of a movable member (actuator) acting on the basis of the driving of the motor. As such a motor, motors which are shown in JP-A-11-215773 and JP-A-11-215774 are proposed. In the case of these motors, as shown in FIG. 10(A), an opening 22a is formed in the peripheral surface of the cylindrical part of a casing 22 where a reduction worm wheel and a rotary shaft worm forming part of the motor are contained. The structure is such that a rotation detecting device 24 is provided on the inside surface of a sensing unit 23 which is formed to close the above described opening 22a, and waterproofing of the rotation detecting device 24 or other members which are arranged in the interior of the casing 22 is achieved by putting a seal member between the peripheral part of the casing opening 22a and the sensing unit 23 to close the opening 22a. 
However, with such a structure as the above described conventional one, the sensing unit 23 in which the rotation detecting device 24 is provided is inserted from the outside of the opening 22a, formed in the peripheral part of the casing 22, and is integrated by fixing means, such as, using screws 25. Therefore, not only the screwing work becomes necessary making the work troublesome but also incurs a risk that the screw 25 is loosened by an external force as the fixing screw 25 is exposed to the outside of the motor. Additionally, the problem that the above described water proof structure must be provided at the boundary part between the casing 22 and the sensing unit 23 is created.
On the other hand, when providing a rotation detecting device, the electrical connection for feeding electricity to the rotation detecting device is necessary. In the case of the conventional one, as shown in FIG. 10 (B), a lead wire 24a is pulled out of the rotation detecting device 24 and is integrated with a lead wire 26 which is separately pulled out for feeding a brush to form an extension harness 27. At the end part of the extension harness 27, a connecting male coupler 28 is provided, and to the male coupler 28, a female coupler which is pulled out from the external power source on the vehicle body side or the like is connected. However, each extension harness 27 is required to have a different length depending on the position where the motor is provided. Therefore, it is necessary to prepare motors in which extension harnesses 27 of various kinds of specifications are provided. Additionally, there are such problems that the number of products becomes large making quality control troublesome, and causing a high cost.
Furthermore, in the case where such a motor is attached to the door of a vehicle or the like, horizontally mirror image casings 22 may be prepared, but the shape of the opening 22a formed in each casing 22 is not horizontally symmetrical. Therefore, there is a problem that a sensing unit 23 with a shape corresponding to each of these openings 22a must be prepared, which makes it difficult to use a common part. The problems to be solved by the invention exist in these points.
The invention is created in view of the situation, having an object of solving the problems discussed above, and it is a motor comprising a rotary shaft; a casing with a bottomed cylindrical part which rotatably contains the rotary shaft; and a rotation detecting device which detects the rotation of the rotary shaft, wherein the rotation detecting device is supported by a sensor holder, and the sensor holder is disposed in the casing by the incorporation(installation) from the incorporating direction to the cylindrical part of the rotary shaft. By doing so, the sensor holder is arranged to be housed in the casing, and it becomes unnecessary to provide a waterproof structure.
In this motor, it is possible that a holder receiving part is formed on the inner peripheral surface of the cylindrical part of the casing of the invention, and that a sensor holder is incorporated in the holder receiving part in a state of temporary holding, and a fixing means for the sensor holder, such as screws, becomes unnecessary.
Furthermore, in the motor, the sensor holder of the invention can be a holder, where a sensor support part in which the rotation detecting device is incorporated and a terminal support part in which a connecting terminal thereof is incorporated are formed, and a connecting opening part for seeing the terminal support part from the outside is formed in the outer peripheral surface of the cylindrical part of the casing.
Furthermore, in the motor, it is possible that, on the opening side of the cylindrical part of the casing of the invention, a brush unit in which a brush is incorporated is fixed, and that the sensor holder in the casing is positioned and supported by the casing on the basis of the fixing to the casing of the brush unit.
Furthermore, in the motor, the structure can be such that the brush connecting terminal incorporated in the brush unit of the invention extends onto the terminal support part of the sensor holder so as to be supported by the terminal support part, and to be seen from the connecting opening part of the casing.
Furthermore, in the motor, the connecting opening part of the casing of the invention can be a part where at least one projecting piece part which projects toward the outside diameter side is formed.
Furthermore, in the motor, an external pull-out terminal unit which is electrically connected to each of the connecting terminals of the rotation detecting device and the brush can be incorporated, in the connecting opening part of the invention, from the outside diameter side of the cylindrical part.
Furthermore, in the motor, the structure can be such that the terminal of the terminal support part of the invention is supported in the state of projecting in the outside diameter direction of the cylindrical part and, on the other hand, a support piece part, which supports the terminal support part of the sensor holder, is formed on the holder receiving part on the bottom side of the cylindrical part, and the incorporation load at the time of incorporating the external pull-out terminal unit to the terminal support part is received by the support piece part through the terminal support part. Thus, the incorporation load acting on the sensor holder to deform the sensor holder is avoided, and the accuracy of the rotation detection can be raised.
Furthermore, in the motor, the structure can be made such that to the external pull-out terminal unit of the invention, at least one engaging claw is formed on the incorporation tip side, and the engaging claw is engaged with the step-like engagement receiving part which is formed to the connecting opening part, when the external pull-out terminal unit is incorporated in the connecting opening part. By doing this, it becomes possible to set an engagement receiving part with which the engaging claw is engaged, without providing an opening which leads to the periphery of the projecting piece part, and the external pull-out terminal unit can be attached to the connecting opening part in a sealing state so that a water proof structure is provided, and the workability can be improved.
Furthermore, in this motor, the engagement receiving part of the invention is formed integrally when the cylindrical part is molded.